Lignin-Mediated Biosynthesis of ZnO and TiO2 Nanocomposites for Enhanced Antimicrobial Activity

Kanchan M Samb-Joshi,Rajendra P Panmand,Suresh P Rasale,Hiralal B Sonawane,Bharat B Kale,Anuradha A Ambalkar,Manohar G Chaskar,Yogesh A Sethi,Rajendra Patil

doi:10.3390/jcs3030090

Abstract

In this work, we report the synthesis of fragmented lignin (FL) assisted zinc oxide (ZnO) and titanium oxide (TiO2) nanocomposites. The fragmented lignin synthesized from biomass (sugarcane bagasse) was used as a template to generate the morphology and crystallite structure of metal oxide nanomaterial. The nanocomposites were synthesized by a simple precipitation method, wherein fragmented lignin is used in alkaline medium as a template. X-ray diffraction (XRD) analysis shows the phase formation of hexagonal wurtzite ZnO and mixed phase formation of TiO2 as rutile and anatase. The morphology was studied by using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). The FE-SEM of pristine ZnO nanocomposites showed a cluster of particles whereas FL–ZnO NPs showed self-aligned nanoparticles in the form of rod shaped having average size 30–70 nm. Pristine TiO2 nanoparticles showed clusters of particles and FL–TiO2 nanocomposites showed well crystalline 41nm size nanocomposites. The FL acts as a surfactant which restrict the cluster formations. The band gap determined by diffuse reflectance spectra is 3.10 eV and 3.20 eV for FL–ZnO and FL–TiO2 nanocomposites, respectively. Photoluminescence spectra of both nanocomposites showed structural defects in the visible region. Further, the antimicrobial activity of pristine ZnO and TiO2 nanoparticles, and FL–ZnO and FL–TiO2 nanocomposites against Escherichia coli (ATCC25922), Staphylococcus aureus (ATCC25923) were studied under UV-A (315-400 nm) (8W) for 30min.

Highlights

One of the greatest challenges of the twenty-first century is the spread of multidrug resistance in microorganisms [1]
In the present work, a simple and environmentally friendly in-situ template fragmented lignin (FL)-assisted synthesis method is reported for controllable preparation of FL–zinc oxide (ZnO) and FL–TiO2 nanocomposites
The FL–ZnO and FL–TiO2 nanocomposites were characterized by UV-Visible, high resolution mass spectrometry (HRMS), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy

Summary

Introduction

One of the greatest challenges of the twenty-first century is the spread of multidrug resistance in microorganisms [1]. Several approaches have been developed for the synthesis of 1D ZnO nanostructures, such as sputtering method, physical, chemical, and pulsed laser vapor deposition [11] Most of these methods often faced with problems such as complex procedures, high temperature, and cost. In chemical-based method, ZnO are synthesized on the template of organic polymer to achieve polydispersity and increase the interface compatibility of nanomaterials with other surfaces. Several natural polymers such as DNA, silk, albumen, orange juice, pea starch, peptide structures, etc., have been used as templates for the synthesis of ZnO [14]. The main objective of this research is to determine the functional significance of fragmented lignin (template) assisted synthesis of ZnO and TiO2 nanocomposites for improving the antimicrobial property of ZnO and TiO2 nanoparticles

Objectives

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Results

Conclusion